What are conditional statements in HTML called?

user_16203234 0
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Recently started to learn HTML, and I saw an example code that contains the following:

{% if greeting %}
    I just wanted to say
    <em style="color: green; font-size: 2em;">{{ greeting }}</em>.
{% else %}
    <em>Hello</em>, world!
{% endif %}

May I know if there is a name for these {% if %} , {% else %} etc. statements in HTML? I know that these are conditional statements in Python/C++, but I can't find much about the HTML version of conditional statements online. Thanks!

html
2 Answers

These are essentially inline expressions. They're not part of HTML itself, even though the expressions seem to be at face value. Instead, they're part of or related to server-side scripting languages such as ASP.NET and PHP.

Depending on the context and language, they may be referred to by different names, such as:

  • Inline expressions
  • Embedded code blocks
  • Tags (embedded tags, template tags)

For example, the ASP.NET documentation categories the usage of <% and %> as inline expressions, but refers to their examples as embedded code blocks. Here is a simplified example:

 <% if (true) { %>
      <b>Hello</b>
 <% } %>

When coding in PHP, these expressions would be called tags (see documentation):

<div>
     <?php if (True): ?> 
          <b>Hello</b>
     <?php endif ?>
</div>

When programming in Jinja (a template engine) for Python (see documentation), we'd call these tags as well:

 <div>
      {% if True %}
           <b>Hello</b>
      {% endif %}
 </div>

The code you have posted is likely from Django's template engine or less likely Jinja, as the code should work with both.

Edit: I forgot to mention HTML conditional comments (see the w3resource), which are limited to detecting whether or not Internet Explorer is being used by the client.

user_46259820

but I can't find much about the HTML version of conditional statements online. Thanks!

obviously you will not be able to find them online by simply searching something like "if statement html" because they are not pure HTML which means those are not the basic html that you use for frontend, those are called django templates which is a python library

here is a reference to the django template

user_153666350
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